The present invention is directed to a water treatment tank apparatus. More specifically, the present invention is directed to a launder channel cover apparatus for use in a water treatment tank.
The necessity for providing sewage treatment plants to clean and purify water discharged from homes and factories is well known. The function of a sewage treatment facility is to receive raw sewage (water containing waste material) as discharged from a city sewage system and clean it to ultimately produce purified water. This is accomplished through a series of biological and mechanical processes.
In a typical water treatment facility, the raw sewage is received from the sewage system and passed through a coarse screen to remove large pieces of matter. The sewage is next directed to one or more primary sedimentation tanks or clarifiers. The sewage remains in primary sedimentation for a period of time sufficient to allow the majority of the heavy matter to settle to the bottom of the tank forming sludge. This sludge is removed for xe2x80x9cdigestionxe2x80x9d by microorganisms. The digested sludge is then dried and can be used as compost or fertilizer. The remaining liquid is treated in a second biological system to remove ammonia. The liquid from this treatment is then aerated and passed into final sedimentation water treatment tanks to remove any remaining solid material.
Water treatment tank configurations vary with each treatment facility application. This notwithstanding, most final sedimentation water treatment tanks are circular. This simplifies automatic skimming, churning and/or bottom scraping operations. More specifically, by eliminating inaccessible corners and providing uniform surfaces, a revolving scraper arm or skimmer blade can provide complete and efficient churning and prevent sludge buildup.
During operation of one type of water treatment tank, water containing sediment enters the center of the tank. In a continuous process, the lighter clean water is effectively decanted from the heavier sediment containing water. More particularly, the clean water is displaced from the tank by the constant flow of water containing sediment into the tank. The displaced clean water is forced to flow under a baffle plate for collecting floating scum and then over a weir, ultimately entering a clean water flow channel. The clean water flow channel directs the water to the next treatment stage where it is chlorinated and further made safe to be discharged into a river or stream.
Presently, algae growth in the trough or launder channel is a serious problem in clarifier tanks. Specifically, as algae builds up on the weirs of the clarifier tank, it can substantially interfere with the hydraulic flow therethrough. Algae typically adheres to the surfaces of the weir and the trough, where it becomes unsightly and odorous. When the launder is cleaned, however, the algae is often loosened and causes clogging of the downstream filters.
For many years, the removing of algae from the baffle, weir, spillway and clean water flow channel has been completed primarily by scrubbing the tank structure with brushes manipulated by hand. Because the final treatment tanks are quite large, this is a labor-intensive and tedious process, involving a large expenditure of man-hours. Additionally, the algae removing process must be done frequently, thereby further adding to the cost.
More recent proposals directed at the problem of algae growth have utilized covers, such as fiberglass covers, which inhibit light from entering the baffle, weir, spillway and clean water flow channel of a circular tank. However, even though those covers prevent light from entering these areas greatly reducing algae production, periodic inspection and cleaning is still necessary. Thus, there is a need to provide not only an inexpensive launder channel cover which not only blocks light from entering the baffle, weir, spillway and the clean water flow channel, but also allows easy access to all of these regions for inspection and cleaning.
However, even with these improvements, algae and other buildup can still accumulate on the weir, spillways and on other portions of the lauder channel. As such, a need arises not only to prevent ultra violet rays from reaching the weir and lauder channel, but also to allow easy access to the entire lauder channel and all of its component parts including the weir and spillway so as to allow for easy cleaning and maintenance.
The present invention is directed to a water treatment tank apparatus including an influent, at least one substantially vertical peripheral wall forming a launder channel having an upper and an interior surface, a substantially vertical weir connected to the vertical peripheral wall, the launder channel having a width. The apparatus is further comprised of a cover section having first and second ends, where the first end is secured to an outer tank wall and the second end positioned over the entire launder channel and radially inwards to a scum baffle and integrated mounting bracket, for preventing light from reaching interior surfaces.
At least one panel member is dimensioned to span the width of the launder channel including a weir and spillway of the channel, and is comprised of a substantially opaque material, whereby the growth of algae on fluid contacting surfaces of the launder channel, weir and spillway is inhibited.
A support flange is provided, coupled to the tank wall, for supporting the first end of the cover section. A bracket mount for attaching the scum baffle with integrated mounting bracket to the vertical peripheral wall is also provided where the scum baffle with integrated mounting bracket has a baffle portion and a mounting bracket portion such that the bracket mount extends away from the peripheral wall for a distance greater than the length of the mounting bracket portion of the scum baffle with integral mounting bracket.
A pivot means is coupled to the mounting bracket portion of the scum baffle with integral mounting bracket and to the cover section for pivoting the cover section away from the outer tank wall about a pivot axis between a first closed position and a second open position so as to allow complete access for cleaning and inspection of the weir, spillway and launder channel.